Breast cancer and ovarian cancer genetics: an update

Investigating men's motivations to engage in genetic screening for BRCA1 and BRCA2 mutations

BRCA1 and BRCA2 mutations are associated with an increased risk of developing numerous cancers, including breast, ovarian, pancreatic, melanoma and prostate cancer. Men face BRCA-related cancer risks as women do. However, there is considerably less research on the psychological determinants of men engaging in BRCA1/2-related cancer prevention compared to women. The present research aimed to study the determinants of men’s motivations to engage in genetic screening for BRCA1 and BRCA2 through the lens of the Health Action Process Approach. One hundred and twenty-five men (mean age = 58.53 y/o, SD = 10.37) completed an online survey. The intention to undergo genetic screening for BRCA1/2 mutations in men was significantly and positively associated with self-efficacy and risk perception. Moreover, having offspring positively affected intention as well. The relationships between intention (and planning) and positive outcome expectancies, age, and family history of breast-related cancer were not statistically significant. Most information on BRCA1 and BRCA2 mutations is tailored to women due to the availability of effective surgical risk reduction procedures for women’s breast and ovarian cancer. Future research should focus on the best methods of communicating informed decision-making for men facing the risk of such mutations.

Comparison of the dermatoglyphic characteristics of women with and without breast cancer

OBJECTIVE

To compare the dermatoglyphic characteristics of women with and without breast cancer.

STUDY DESIGN

Case-control study. One hundred and thirty women=130 women with histopathologically confirmed breast cancer (case group) were compared with 127 women in the same age group but without breast cancer (control group). Fingerprints of the two groups were compared in terms of whorl, loop and arch patterns.

RESULTS

The loop pattern was most common in both groups [68 women (52.3%) in the case group and 58 women (45.7%) in the control group], followed by the whorl pattern [60 women (46.2%) in the case group and 64 women (50.4%) in the control group]; the difference was not significant (p=0.337). The number of whorl patterns and the breakdown by classification group did not differ significantly between the two groups. In addition, no significant difference was found in the dermatologlyphic patterns of the women with breast cancer with and without a family history of breast cancer.

CONCLUSION

No difference was found in the dermatoglyphic characteristics of women with and without breast cancer. As such, this does not appear to be an effective screening method for women at risk for breast cancer.

Cell cycle-dependent regulation of the bi-directional overlapping promoter of human BRCA2/ZAR2 genes in breast cancer cells

Background

BRCA2 gene expression is tightly regulated during the cell cycle in human breast cells. The expression of BRCA2 gene is silenced at the G0/G1 phase of cell growth and is de-silenced at the S/G2 phase. While studying the activity of BRCA2 gene promoter in breast cancer cells, we discovered that this promoter has bi-directional activity and the product of the reverse activity (a ZAR1-like protein, we named ZAR2) silences the forward promoter at the G0/G1 phase of the cell. Standard techniques like cell synchronization by serum starvation, flow cytometry, N-terminal or C-terminal FLAG epitope-tagged protein expression, immunofluorescence confocal microscopy, dual luciferase assay for promoter evaluation, and chromatin immunoprecipitation assay were employed during this study.

Results

Human BRCA2 gene promoter is active in both the forward and the reverse orientations. This promoter is 8-20 fold more active in the reverse orientation than in the forward orientation when the cells are in the non-dividing stage (G0/G1). When the cells are in the dividing state (S/G₂), the forward activity of the promoter is 5-8 folds higher than the reverse activity. The reverse activity transcribes the ZAR2 mRNA with 966 nt coding sequence which codes for a 321 amino acid protein. ZAR2 has two C4 type zinc fingers at the carboxyl terminus. In the G0/G1 growth phase ZAR2 is predominantly located inside the nucleus of the breast cells, binds to the BRCA2 promoter and inhibits the expression of BRCA2. In the dividing cells, ZAR2 is trapped in the cytoplasm.

Conclusions

BRCA2 gene promoter has bi-directional activity, expressing BRCA2 and a novel C4-type zinc finger containing transcription factor ZAR2. Subcellular location of ZAR2 and its expression from the reverse promoter of the BRCA2 gene are stringently regulated in a cell cycle dependent manner. ZAR2 binds to BRCA2/ZAR2 bi-directional promoter in vivo and is responsible, at least in part, for the silencing of BRCA2 gene expression in the G0/G1 phase in human breast cells.